If it were me I would choose a regional in this order:

-Base (commuting is horrible)..pick a regional that has a base that you could see yourself living in for a long time just in case you never get a call from a major. Some guys are surprised after being at a regional for a few years that they haven’t received a call. The commuting guys are miserable. For me, anything under a 2 hour drive I would also consider.

-Contract: Not all regionals are created equal. Work rules are better are better at some places than others. This could translate into more or less days at home, pay, or abilities for the company to do whatever they want with you. Contracts change though. Right now Republic, Skywest, Endeavor seem to have the best ones, that could easily change though with next negotiations though. Worse contracts seem to point to WO.

-Flow...if you want to go to American really really badly, I would highly consider a WO. Not guaranteed you’ll flow, but your chances of getting on with American are greatly improved there vs off the street at another regional. You will be sacrificing contract though.

Looking through everyone’s replies to your post, almost everyone is saying base or that commuting sucks. I cannot stress this enough-don’t commute. Totally different job, a million times more stressful and you’ll never be home. Pick the regional with the best base and stick to it. Contracts, pay, airframes all change at the end of the day it’s a job, try to pick a place where you can really enjoy life on your days off-not being stuck at airports trying to get home. Good luck